A Gracious Host: La Jollan plants milkweed for monarch butterflies

In an effort to attract and provide a breeding place for the fiery-colored monarch butterfly, La Jollan Mary Ellen Morgan has dedicated a part of her garden to planting milkweed. Considered a “host plant” for the monarchs, milkweed provides a place for monarch caterpillars to grow and thrive before embarking on their transformative journeys.

Her efforts started by accident three years ago. “I went to a nursery just looking for flowers for my flowerbed, and I found this pretty plant, so I took it home,” she said. “One day I walked past the flowerbed and my really pretty plant had the leaves eaten off and there were all these caterpillars.”

She looked online for the type of caterpillar that had devoured her plant and realized they were monarch caterpillars, ones that would eventually become monarch butterflies.

“Before I knew it, I had all these butterflies flying around my yard,” she said. She continued to purchase milkweed and nectar plants to feed the butterflies.

“It’s been really easy and really fun, and I’ve invited kids to come and see this,” she said. “If children wanted to do this at home, all their parents or schools would have to do is go and buy some milkweed ... there are monarch preservation associations that will send you seedlings for a dollar a plant.”

Milkweed plants, said David Marriott, director and founder of the San Diego-based Monarch Program, are a host for monarchs in all cycles of life — and ones that monarchs know how to find and return to.

Butterflies lay their eggs on the leaves, which hatch after a few days into larvae. The larvae then eat the leaves to grow and become caterpillars. As caterpillars, they continue to eat the milkweed plant before they enter the pupa stage and hang from the plants — or whatever else is stable and nearby — as the caterpillars envelope themselves in a chrysalis, where they remain until they emerge as a butterfly. Marriott said that because the caterpillars eat the leaves off the plant, milkweed needs to be repurchased and replanted annually.

He noted that different plants will attract different types of butterflies. Passionflower vines, for example, can be a host plant for a black-and-yellow striped butterfly, called the zebra longwing, and checkered white. For those who want to foster monarchs, he advises obtaining the milkweed from a source that does not spray them with pesticides because some nurseries spray milkweed to prevent other bug species from latching on, and those pesticides can kill the caterpillars. Morgan said she doesn’t use pesticides on her yard because of her dogs. In late May this year, she reported 50 caterpillars on her plants, several of which have since entered the chrysalis stage.

So, if you see a monarch butterfly floating around La Jolla in the coming weeks, it may have come from Morgan’s garden!